nodejs: fix build when python3 is selected in Buildroot

When Python 3 is selected in Buildroot, the host/usr/bin/python
symlink of the host Python interpreter points to python3. Packages
that need to use the host Python 2 interpreter have to use python2.

In commit 40218a16526946f35dab0d05f379f71a01f29530 ("nodejs: force
python interpreter"), Samuel made some changes to the nodejs package
to use python2. One part of the changes is to sed a .gyp file to
replace the string 'python' by the path to python2. However, this
operation is done *after* calling the configure script, so it has in
fact no effect. Putting this sed before calling the configure script
fixes the problem.

However, there is a better solution: the nodejs build system has a
mechanism of variables, and it already defines a python variable
according to the environment variable PYTHON being passed. So this
patch instead adds a new patch to nodejs to use this python variable.

Fixes:

  http://autobuild.buildroot.org/results/aff/affd7300895ec400de50a33d51b4e94e15d63341/

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
---
 .../nodejs/nodejs-0003-use-python-variable.patch   | 43 ++++++++++++++++++++++
 package/nodejs/nodejs.mk                           |  2 -
 2 files changed, 43 insertions(+), 2 deletions(-)
 create mode 100644 package/nodejs/nodejs-0003-use-python-variable.patch

HI Thomas,

On Tue, May 20, 2014 at 10:30:14PM +0200, Thomas Petazzoni wrote:
> When Python 3 is selected in Buildroot, the host/usr/bin/python
> symlink of the host Python interpreter points to python3. Packages
> that need to use the host Python 2 interpreter have to use python2.
> 
> In commit 40218a16526946f35dab0d05f379f71a01f29530 ("nodejs: force
> python interpreter"), Samuel made some changes to the nodejs package
> to use python2. One part of the changes is to sed a .gyp file to
> replace the string 'python' by the path to python2. However, this
> operation is done *after* calling the configure script, so it has in
> fact no effect. Putting this sed before calling the configure script
> fixes the problem.
> 
> However, there is a better solution: the nodejs build system has a
> mechanism of variables, and it already defines a python variable
> according to the environment variable PYTHON being passed. So this
> patch instead adds a new patch to nodejs to use this python variable.
> 
> Fixes:
> 
>   http://autobuild.buildroot.org/results/aff/affd7300895ec400de50a33d51b4e94e15d63341/
> 
> Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
> ---
>  .../nodejs/nodejs-0003-use-python-variable.patch   | 43 ++++++++++++++++++++++
>  package/nodejs/nodejs.mk                           |  2 -
>  2 files changed, 43 insertions(+), 2 deletions(-)
>  create mode 100644 package/nodejs/nodejs-0003-use-python-variable.patch
> 
> diff --git a/package/nodejs/nodejs-0003-use-python-variable.patch b/package/nodejs/nodejs-0003-use-python-variable.patch
> new file mode 100644
> index 0000000..f231f4c
> --- /dev/null
> +++ b/package/nodejs/nodejs-0003-use-python-variable.patch
> @@ -0,0 +1,43 @@
> +Use a python variable instead of hardcoding Python
> +
> +The nodejs build system uses python in a number of locations. However,
> +there are some locations where it hardcodes 'python' as the Python
> +interpreter. However, this causes problems when we need to use python2
> +instead of just python.
> +
> +This patch fixes that by using the python variable already in place in
> +the nodejs build system.
> +
> +Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
> +
> +Index: b/deps/v8/tools/gyp/v8.gyp
> +===================================================================
> +--- a/deps/v8/tools/gyp/v8.gyp
> ++++ b/deps/v8/tools/gyp/v8.gyp
> +@@ -792,7 +792,7 @@
> +                 '<(SHARED_INTERMEDIATE_DIR)/libraries.cc',
> +               ],
> +               'action': [
> +-                'python',
> ++                '<(python)',
> +                 '../../tools/js2c.py',
> +                 '<@(_outputs)',
> +                 'CORE',
> +@@ -810,7 +810,7 @@
> +                 '<(SHARED_INTERMEDIATE_DIR)/experimental-libraries.cc',
> +               ],
> +               'action': [
> +-                'python',
> ++                '<(python)',
> +                 '../../tools/js2c.py',
> +                 '<@(_outputs)',
> +                 'EXPERIMENTAL',
> +@@ -840,7 +840,7 @@
> +                   '<(SHARED_INTERMEDIATE_DIR)/debug-support.cc',
> +                 ],
> +                 'action': [
> +-                  'python',
> ++                  '<(python)',
> +                   '../../tools/gen-postmortem-metadata.py',
> +                   '<@(_outputs)',
> +                   '<@(heapobject_files)'
> diff --git a/package/nodejs/nodejs.mk b/package/nodejs/nodejs.mk
> index b5973b5..7415bdf 100644
> --- a/package/nodejs/nodejs.mk
> +++ b/package/nodejs/nodejs.mk
> @@ -35,8 +35,6 @@ define HOST_NODEJS_CONFIGURE_CMDS
>  		--without-dtrace \
>  		--without-etw \
>  	)
> -	$(SED) "s@'python',@'$(HOST_DIR)/usr/bin/python2',@" \
> -		$(@D)/deps/v8/tools/gyp/v8.gyp

The comment above 'define HOST_NODEJS_CONFIGURE_CMDS' should be updated to 
match.

baruch

>  endef
>  
>  define HOST_NODEJS_BUILD_CMDS

Dear Baruch Siach,

On Wed, 21 May 2014 05:52:43 +0300, Baruch Siach wrote:

> > diff --git a/package/nodejs/nodejs.mk b/package/nodejs/nodejs.mk
> > index b5973b5..7415bdf 100644
> > --- a/package/nodejs/nodejs.mk
> > +++ b/package/nodejs/nodejs.mk
> > @@ -35,8 +35,6 @@ define HOST_NODEJS_CONFIGURE_CMDS
> >  		--without-dtrace \
> >  		--without-etw \
> >  	)
> > -	$(SED) "s@'python',@'$(HOST_DIR)/usr/bin/python2',@" \
> > -		$(@D)/deps/v8/tools/gyp/v8.gyp
> 
> The comment above 'define HOST_NODEJS_CONFIGURE_CMDS' should be updated to 
> match.

Ah, right, indeed. Will send a v2.

Thomas